Combined voltage regulator and amplifier



Oct. 9, 1956 R. A. HENDERSON ,76 32 COMBINED VOLTAGE REGULATOR AND AMPLIFIER Filed Dec. 29, 1953 FECEII f i ff f2 PMF/Y Sam/rm SUPPLY BY i f ZTTORNEY United States Patent Ofiice 2,766,332 Patented Oct. 9, 1956 COMBINED VOLTAGE REGULATOR AND AMPLIFIER Roy A. Henderson, West Collingswood, N. J., assignor, by mesne assignments, to the United States of America as represented by the Secretary of the Army Application December 29, 1953, Serial No. 401,010 6 Claims. (Cl. 179-171) This invention relates generally to a combined voltage regulator and amplifier, and more particularly to an improved combination of a regulated unidirectional power supply and a push pull amplifier wherein the latter functions as a part of the former. While neither specifically nor exclusively limited thereto, the unique combination of a voltage regulator and amplifier of the present invention is particularly useful in decreasing the cost and weight of transceivers, walkie-talkies, and the like, and in increasing their efficiency.

In certain types of electronic equipment, as in mobile transceivers, for example, it is necessary to supply certain utilization circuits with substantially constant unidirectional voltages. is necessary to supply the receiver section thereof with a substantially constant regulated voltage input. Since this regulated voltage is usually obtained from a battery and a vibrator power pack in the usual manner, it is desirable to have a regulator circuit for maintaining the unidirectional voltage substantially constant. When the usual regulatory circuit, of the type comprising a variable impedance series tube, is used, the relatively large voltage drop across this tube is normally wasted power. Since the walkie-talkie is designed to be carried by an individual,

. it is extremely important to reduce its weight without reducing its efliciency.

It is, therefore, a principal object of the present invention to provide an proved combined voltage regulator and amplifier wherein the latter also functions as a variable impedance element in the former.

It is another object of the present invention to provide :an improved combined voltage regulator and amplifier wherein the power Wasted by the voltage drop across the series regulator tube in the former is utilized for the operation of the latter in push pull.

It is a further object of the present invention to provide an improved combined voltage regulator and amplifier wherein the plate voltage across the series regulator tube of the former is utilized to power the latter as a push pull amplifier.

Still another object of the present invention is to provide an improved combination of a voltage regulator and push pull amplifier wherein there is a conservation of power and parts resulting from the elimination of com ponents used heretofore.

Still a further object of the present invention is to provide an improved combined voltage regulator and audio amplifier which is simple in construction, economical to manufacture, and yet highly efiicient in use.

In general, the foregoing and other objects and advantages of the present invention are accomplished by an improved combined voltage regulator and push pull audio amplifier wherein the latter functions as the variable impedance series regulator tube of the former. In prior art regulatory circuits for providing a substantially constant unidirectional voltage output from an A. C. source, a variable impedance series regulator tube is connected between a source of unregulated unidirectional voltage In some walkie-talkies, for example, it

and the positive output terminal. A considerable amount of energy is consumed or wasted by the voltage drop across this variable impedance series regulator tube. In accordance with the present invention, the voltage drop' across the variable impedance series regulator tube, which is normally wasted, is salvaged by a novel circuit utilizing this tube as a push pull amplifier for a utilization circuit, such as a radio receiver in a walkie-talkie. The regulated output voltage of the voltage regulator is applied to the input of the radio receiver. The signal output of the radio receiver is coupled to the grids of a twin triode through a transformer, in push pull fashion. The triodes of the twin triode tube are connected in parallel with each other and in series between the source of unregulated voltage and an output terminal of the voltage regulator circuit, as series regulator tubes. Translated signals are derived from the twin triodes through an output transformer coupling the anodes thereof to a speaker.

The novel features of the invention, as well as the invention itself, both as to its organization and method of operation, will be understood in detail from the following description when considered in connection with the accompanying drawing which is a schematic diagram, partly in block diagram form, of the combined voltage regulator and amplifier, in accordance with the present invention. Referring now to the drawing, there is shown a source of unregulated unidirectional voltage 10 having a positive output terminal 12 and a negative output terminal 14. The source of unregulated unidirectional voltage 10- directional voltage, in a manner to be described. The negative terminal 14. of the source 10 is connected to the regulated output voltage terminal 16. The positive output terminal 12 of the source 10 is connected to the center tap of a center tapped primary winding 20 of an output transformer 22. Each of the ends of the center tapped primary winding 20 is connected to a separate anode of a twin triode,'or duotriode 24. The duotriode 24 is a variable impedance device. Two separate tubes, each having at least three elements, may be used instead of the duotriode 24 within one envelope, as illustrated. The cathodes of the duotriode are connected to each other and to the regulated output voltage terminal 18. Each of the ends of a center tapped secondary Winding 26 of an input transformer 28 is connected to a separate grid of the duotriode 24. Thus, it will be understood that the triodes of the duotriode 24 are connected in parallel with each other and inseries with the source of unregulated unidirectional voltage 10 and the regulated output voltage terminals 16 and 18.

Means are provided to vary the variable impedance of each of the triodes of the duotriode 24 degeneratively in accordance with changes in the output voltage across the regulated output voltage terminals 16 and 18. To this end, there is provided a between the terminals 16 and 18. A sample of the regulated output voltage across the terminals 16 and 18 is taken by the variable tap of the potentiometer 30 and applied to the grid of a control tube 32. The anode of the control tube is connected directly to the center tap of the center tap secondary 26 of the input transformer 28, and to the regulated output voltage terminal 18 through a load resistor 34. A capacitor 36 is connected across the load resistor 34. Y

A capacitor 38 is connected voltage terminals 16 and 18 across the regulated output for filtering purposes. Re-

18 are provided across which. there is obtained a substantially constant regulated unipotentiometer 30 connected:

sistors 40, 42 and 44, connected in series with each other, are also connected across the regulated output voltage terminals 16 and 18. The voltage drop across the resistors 42 and 44 is maintained substantially constant by a voltage regulator tube 46 connected between the junction of resistors 40 and 42 and the regulated output voltage terminal 16. The cathode of the control tube 32 is maintained substantially constant by connecting it to the junction between the resistors 42 and 44. With this arrangement, it will be understood that any change in the regulated output voltage across the terminals 16 and 18 will result in a relative change in a signal applied to the grid of the control tube 32 with respect to the cathode thereof.

The operation of the regulated power supply, in accordance with the present invention, will now be described. Let it be assumed that there is a tendency for the regulated output voltage across the terminals 16 and 18 to increase, due to either a decrease in the load or to an increase in voltage of the source of unregulated, unidirectional voltage 10. As a result, the sample voltage applied to the grid of the control tube 32 will increase. The output signal from the anode of the control tube 32 will be a negative-going signal applied to the control grids of the duotriode 24, thereby increasing the internal impedance of the duotriode 24. The current flowing through the triodes of the duotriode 24 will now decrease, thereby decreasing the voltage across the regulated output voltage terminals l6 and 18. Any tendency for the regulated output voltage across the terminals 16 and 18 to decrease will result in a positive-going signal at the grids of the triodes of the duotriode 24. The resulting decrease in the impedance of the variable impedance device 24 will cause more current to flow, thereby tending to restore the output voltage across the terminals 16 and 18 to a substantially constant output voltage.

The voltage drop across the duotriode 24 is usually wasted power. For instance, where the output voltage of the source of unregulated voltage 10 is 300 volts, and a regulated output voltage across the terminals 16 and 18 is 65 volts, the voltage drop across the duotriode 24, that is wasted, is about 235 volts. In accordance with the present invention, the voltage drop across the series regulator tube 24, that is normally wasted, is now salvaged by using it to translate signals from one utilization circuit to another utilization circuit. In a walkie-talkie, for example, the receiver 48 thereof is a utilization circuit which is powered by the regulated voltage output of the regulated power supply.

The regulated output voltage terminals 16 and 18 are connected to input terminals 50 and 52, respectively, of the receiver 48. Portions of the walkie-talkie equipment of which the receiver 48 is a part may also require a high unregulated voltage. To this end, the output terminal 12 of the source of unregulated voltage 10 is connected to an input terminal 54. The receiver 48, which may be considered an electronic utilization circuit has output means in the form of output terminals 56 and 58. The ends of a primary winding 60 of the input transformer 28 are connected to the output terminals 56 and 58, respectively, of the receiver 48. Thus, the radio signals detected and amplified by the receiver 48. in a manner well known in the art, are applied to the primary winding 60 of the input transformer 28. It will be understood that the duotriode 24 is now connected as av push pull audio amplifier and functions to translate the signals applied to its grids to output signals in its anode circuits.

Since the triodes of the duotriode 24 are connected to operate in push-pull, a decrease in the impedance of one section of the tube, because of an increased positive signal on one grid, will be offset by an increase in the impedance of the other section of the tube resulting from a simultaneous decrease in the grid potential of the other grid. Thus, the impedance of the duotriode 24 will not be changed materially because of its functioning as a push pull amplifier, during its simultaneous functioning as a variable impedance series regulator tube in a voltage regulator circuit. Translated output signals from the anodes of the duotriode 24 are coupled to a utilization circuit, such as a speaker 64, through a secondary winding 62 of the output transformer 22.

The duotriode 24 may be used as a servo-amplifier to amplify control signals, and the speaker 64 may be replaced by a relay or a motor, if desired.

By providing a circuit whereby the duotriode 24 functions both as a series regulator tube for regulating a power supply and as a push pull amplifier for the radio receiver 48, the power that is normally wasted by the series regulator tube 24 is now utilized. In the case of a mobile transceiver, such as a Walkie-talkie, the usual output amplifier stage of the receiver may be eliminated by salvaging the power wasted by the duotriode 24 and by using the duotriode 24 as an output push pull amplifier stage. This not only results in the saving of at least one tube for the receiver, but also results in a saving of the power that would ordinarily be consumed by the eliminated components.

Thus, there has been shown and described, in accordance objects of the present invention, a combined voltage regulator and amplifier. A push pull audio amplifier circuit and series regulator tube circuit are made operative simultaneously by sharing the same tube. The normally wasted plate voltage and current of the usual series regulator tube in a power supply regulator circuit is utilized to power an audio amplifier in push pull, thereby eliminating a push pull amplifier output stage in a utilization circuit, such as a radio receiver. By eliminating the output stage in a radio receiver, for example, there results an appreciable saving of filament and plate power, and also a reduction in the weight of the total equipment.

What is claimed is:

1. In combination, a source of unregulated unidirectional voltage, a pair of regulated output voltage terminals. a pair of variable impedance devices each having an anode, a grid and a cathode, means connecting said devices in parallel with each other and in series with said source and said terminals, means connected between said terminals and said grids to vary the impedance of said devices with changes in voltage between said terminals, utilization circuit means having an input connected to said terminals and an output coupled to said grids to apply signals to said grids in push pull, and signal output means coupled to said anodes to derive said signals in translated form.

2. In combination, a source of unregulated unidirectional voltage, a pair of regulated output voltage terminals, a pair of variable impedance devices each having an anode. a grid and a cathode, means connecting said devices in parallel with each other and in series with said source and said terminals, means connected between said terminals and said grids to vary the impedance of said devices with changes in voltage between said terminals, signal receiving means having input terminals connected to said regulated output voltage terminals and signal output terminals coupled to said grids in push pull, and means to couple a signal utilization circuit to said anodes.

3. In combination, a source of unregulated unidirectional voltage having positive and negative terminals. a pair of regulated output voltage terminals, :1 pair of variable impedance devices each having an anode, a grid and a cathode, an output transformer having a center tapped primary winding and a secondary winding. the center tap of said center tapped primary winding being connected to said positive terminal of said source, each of the ends of said center tapped primary winding being connected to a separate one of said anodes, an input transformer having a primary winding and a center tapped secondary winding, each of the ends of said center tapped secondary winding being connected to a separate one of said grids, said cathodes being connected to each other and to one of said regulated output voltage terminals, said negative terminal of said source being connected to the other of said regulated output voltage terminals, means connecting said center tap of said center tapped secondary winding and said regulated output voltage terminals to feed back degeneratively to said grids a sample of the output voltage between said regulated output voltage terminals, first utilization circuit means having input terminals connected to said regulated output voltage terminals and output terminals connected to said primary winding of said input transformer to apply signals to said grids in push pull, and second utilization circuit means coupled to said secondary winding of said output transformer to derive amplified signals therefrom.

4. In combination, a source of unregulated unidirectional voltage having positive and negative terminals, a pair of regulated output voltage terminals, a pair of variable impedance devices each having an anode, a grid and a cathode, an output transformer having a center tapped primary winding and a secondary winding, the center tap of said center tapped primary winding being connected to said positive terminal of said source, each of the ends of said center tapped primary winding being connected to a separate one of said anodes, an input transformer having a primary winding and a center tapped secondary winding, each of the ends of said center tapped secondary winding being connected to a separate one of said grids, said cathodes being connected to each other and to one of said regulated output voltage terminals, said negative terminal of said source being connected to the other of said regulated output voltage terminals, means connecting said center tap of said center tapped secondary winding and said output terminals to feed back degeneratively to said grids a sample of the output voltage between said regulated output voltage terminals, signal receiving means having input terminals connected to said regulated output voltage terminals and signal output terminals connected to said primary Winding of said input transformer, and signal utilization means connected to said secondary winding of said output transformer.

5. In combination, a regulated unidirectional voltage power supply comprising a source of unregulated unidirectional voltage having positive and negative terminals, a pair of regulated output voltage terminals between which to derive said regulated unidirectional output voltage, a first transformer having a center tapped primary winding and a secondary winding, a pair of electron discharge devices each having an anode, a grid and a cathode, the

cathodes of said devices being connected to each other and to one of said regulated output voltage terminals, said negative terminal of said source being connected to the other of said regulator output voltage terminals, each of the ends of said center tapped primary Winding being connected to a separate one of said anodes, the center tap of said center tapped primary winding being connected to said positive terminal of said source, a second transformer having a primary winding and a center tapped secondary winding, each of the ends of said center tapped secondary winding being connected to a separate one of said grids, means connecting the center tap of said center tapped secondary winding and said regulated output voltage terminals to feed back degeneratively to said grids a sample of said output voltage to vary the impedance of said devices with changes in voltage between said regulated output voltage terminals, a first utilization circuit having input terminals connected to said regulated output voltage terminals and signal output terminals connected to said primary Winding, and a second utilization circuit having input means connected to said secondary winding.

6. In apparatus of the type adapted to receive electrical signals and to provide an amplified output of said signals, a regulated unidirectional power supply comprising a source of unregulated unidirectional voltage, a pair of regulated voltage output terminals, variable impedance means having an input and an output, said variable impedance means being connected in series with said source and said terminals, and means connected between said terminals and to said input of said variable impedance means to vary the impedance of the latter in accordance with voltage changes between said terminals, signal receiving means having power input means connected to said terminals and signal output means coupled to said input of said variable impedance means, and means to derive amplified output signals coupled to said output of said variable impedance means.

References Cited in the file of this patent UNITED STATES PATENTS 2,154,200 Dow Apr. 11, 1939 2,238,259 Hagen Apr. 15, 1941 2,542,293 Smith et al. Feb. 20, 1951 2,598,221 Burton May 27, 1952 2,624,038 Kurshan Dec. 30, 1952 

